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Import OpenSSH-5.1p1.
[dragonfly.git] / crypto / openssh-3.8.1p1 / ssh-agent.c
blobf5fce6b2aa016d7f2dd4d9621d2efce583ee73c8
1 /*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 * The authentication agent program.
6 *
7 * As far as I am concerned, the code I have written for this software
8 * can be used freely for any purpose. Any derived versions of this
9 * software must be clearly marked as such, and if the derived work is
10 * incompatible with the protocol description in the RFC file, it must be
11 * called by a name other than "ssh" or "Secure Shell".
12 *
13 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 #include "includes.h"
37 #include "openbsd-compat/sys-queue.h"
38 RCSID("$OpenBSD: ssh-agent.c,v 1.117 2003/12/02 17:01:15 markus Exp $");
39
40 #include <openssl/evp.h>
41 #include <openssl/md5.h>
42
43 #include "ssh.h"
44 #include "rsa.h"
45 #include "buffer.h"
46 #include "bufaux.h"
47 #include "xmalloc.h"
48 #include "getput.h"
49 #include "key.h"
50 #include "authfd.h"
51 #include "compat.h"
52 #include "log.h"
53 #include "readpass.h"
54 #include "misc.h"
55
56 #ifdef SMARTCARD
57 #include "scard.h"
58 #endif
59
60 #if defined(HAVE_SYS_PRCTL_H)
61 #include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
62 #endif
63
64 typedef enum {
65 AUTH_UNUSED,
66 AUTH_SOCKET,
67 AUTH_CONNECTION
68 } sock_type;
69
70 typedef struct {
71 int fd;
72 sock_type type;
73 Buffer input;
74 Buffer output;
75 Buffer request;
76 } SocketEntry;
77
78 u_int sockets_alloc = 0;
79 SocketEntry *sockets = NULL;
80
81 typedef struct identity {
82 TAILQ_ENTRY(identity) next;
83 Key *key;
84 char *comment;
85 u_int death;
86 u_int confirm;
87 } Identity;
88
89 typedef struct {
90 int nentries;
91 TAILQ_HEAD(idqueue, identity) idlist;
92 } Idtab;
93
94 /* private key table, one per protocol version */
95 Idtab idtable[3];
96
97 int max_fd = 0;
98
99 /* pid of shell == parent of agent */
100 pid_t parent_pid = -1;
101
102 /* pathname and directory for AUTH_SOCKET */
103 char socket_name[1024];
104 char socket_dir[1024];
105
106 /* locking */
107 int locked = 0;
108 char *lock_passwd = NULL;
109
110 #ifdef HAVE___PROGNAME
111 extern char *__progname;
112 #else
113 char *__progname;
114 #endif
115
116 /* Default lifetime (0 == forever) */
117 static int lifetime = 0;
118
119 static void
120 close_socket(SocketEntry *e)
121 {
122 close(e->fd);
123 e->fd = -1;
124 e->type = AUTH_UNUSED;
125 buffer_free(&e->input);
126 buffer_free(&e->output);
127 buffer_free(&e->request);
128 }
129
130 static void
131 idtab_init(void)
132 {
133 int i;
134
135 for (i = 0; i <=2; i++) {
136 TAILQ_INIT(&idtable[i].idlist);
137 idtable[i].nentries = 0;
138 }
139 }
140
141 /* return private key table for requested protocol version */
142 static Idtab *
143 idtab_lookup(int version)
144 {
145 if (version < 1 || version > 2)
146 fatal("internal error, bad protocol version %d", version);
147 return &idtable[version];
148 }
149
150 static void
151 free_identity(Identity *id)
152 {
153 key_free(id->key);
154 xfree(id->comment);
155 xfree(id);
156 }
157
158 /* return matching private key for given public key */
159 static Identity *
160 lookup_identity(Key *key, int version)
161 {
162 Identity *id;
163
164 Idtab *tab = idtab_lookup(version);
165 TAILQ_FOREACH(id, &tab->idlist, next) {
166 if (key_equal(key, id->key))
167 return (id);
168 }
169 return (NULL);
170 }
171
172 /* Check confirmation of keysign request */
173 static int
174 confirm_key(Identity *id)
175 {
176 char *p, prompt[1024];
177 int ret = -1;
178
179 p = key_fingerprint(id->key, SSH_FP_MD5, SSH_FP_HEX);
180 snprintf(prompt, sizeof(prompt), "Allow use of key %s?\n"
181 "Key fingerprint %s.", id->comment, p);
182 xfree(p);
183 p = read_passphrase(prompt, RP_ALLOW_EOF);
184 if (p != NULL) {
185 /*
186 * Accept empty responses and responses consisting
187 * of the word "yes" as affirmative.
188 */
189 if (*p == '\0' || *p == '\n' || strcasecmp(p, "yes") == 0)
190 ret = 0;
191 xfree(p);
192 }
193 return (ret);
194 }
195
196 /* send list of supported public keys to 'client' */
197 static void
198 process_request_identities(SocketEntry *e, int version)
199 {
200 Idtab *tab = idtab_lookup(version);
201 Identity *id;
202 Buffer msg;
203
204 buffer_init(&msg);
205 buffer_put_char(&msg, (version == 1) ?
206 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
207 buffer_put_int(&msg, tab->nentries);
208 TAILQ_FOREACH(id, &tab->idlist, next) {
209 if (id->key->type == KEY_RSA1) {
210 buffer_put_int(&msg, BN_num_bits(id->key->rsa->n));
211 buffer_put_bignum(&msg, id->key->rsa->e);
212 buffer_put_bignum(&msg, id->key->rsa->n);
213 } else {
214 u_char *blob;
215 u_int blen;
216 key_to_blob(id->key, &blob, &blen);
217 buffer_put_string(&msg, blob, blen);
218 xfree(blob);
219 }
220 buffer_put_cstring(&msg, id->comment);
221 }
222 buffer_put_int(&e->output, buffer_len(&msg));
223 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
224 buffer_free(&msg);
225 }
226
227 /* ssh1 only */
228 static void
229 process_authentication_challenge1(SocketEntry *e)
230 {
231 u_char buf[32], mdbuf[16], session_id[16];
232 u_int response_type;
233 BIGNUM *challenge;
234 Identity *id;
235 int i, len;
236 Buffer msg;
237 MD5_CTX md;
238 Key *key;
239
240 buffer_init(&msg);
241 key = key_new(KEY_RSA1);
242 if ((challenge = BN_new()) == NULL)
243 fatal("process_authentication_challenge1: BN_new failed");
244
245 (void) buffer_get_int(&e->request); /* ignored */
246 buffer_get_bignum(&e->request, key->rsa->e);
247 buffer_get_bignum(&e->request, key->rsa->n);
248 buffer_get_bignum(&e->request, challenge);
249
250 /* Only protocol 1.1 is supported */
251 if (buffer_len(&e->request) == 0)
252 goto failure;
253 buffer_get(&e->request, session_id, 16);
254 response_type = buffer_get_int(&e->request);
255 if (response_type != 1)
256 goto failure;
257
258 id = lookup_identity(key, 1);
259 if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
260 Key *private = id->key;
261 /* Decrypt the challenge using the private key. */
262 if (rsa_private_decrypt(challenge, challenge, private->rsa) <= 0)
263 goto failure;
264
265 /* The response is MD5 of decrypted challenge plus session id. */
266 len = BN_num_bytes(challenge);
267 if (len <= 0 || len > 32) {
268 logit("process_authentication_challenge: bad challenge length %d", len);
269 goto failure;
270 }
271 memset(buf, 0, 32);
272 BN_bn2bin(challenge, buf + 32 - len);
273 MD5_Init(&md);
274 MD5_Update(&md, buf, 32);
275 MD5_Update(&md, session_id, 16);
276 MD5_Final(mdbuf, &md);
277
278 /* Send the response. */
279 buffer_put_char(&msg, SSH_AGENT_RSA_RESPONSE);
280 for (i = 0; i < 16; i++)
281 buffer_put_char(&msg, mdbuf[i]);
282 goto send;
283 }
284
285 failure:
286 /* Unknown identity or protocol error. Send failure. */
287 buffer_put_char(&msg, SSH_AGENT_FAILURE);
288 send:
289 buffer_put_int(&e->output, buffer_len(&msg));
290 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
291 key_free(key);
292 BN_clear_free(challenge);
293 buffer_free(&msg);
294 }
295
296 /* ssh2 only */
297 static void
298 process_sign_request2(SocketEntry *e)
299 {
300 u_char *blob, *data, *signature = NULL;
301 u_int blen, dlen, slen = 0;
302 extern int datafellows;
303 int ok = -1, flags;
304 Buffer msg;
305 Key *key;
306
307 datafellows = 0;
308
309 blob = buffer_get_string(&e->request, &blen);
310 data = buffer_get_string(&e->request, &dlen);
311
312 flags = buffer_get_int(&e->request);
313 if (flags & SSH_AGENT_OLD_SIGNATURE)
314 datafellows = SSH_BUG_SIGBLOB;
315
316 key = key_from_blob(blob, blen);
317 if (key != NULL) {
318 Identity *id = lookup_identity(key, 2);
319 if (id != NULL && (!id->confirm || confirm_key(id) == 0))
320 ok = key_sign(id->key, &signature, &slen, data, dlen);
321 }
322 key_free(key);
323 buffer_init(&msg);
324 if (ok == 0) {
325 buffer_put_char(&msg, SSH2_AGENT_SIGN_RESPONSE);
326 buffer_put_string(&msg, signature, slen);
327 } else {
328 buffer_put_char(&msg, SSH_AGENT_FAILURE);
329 }
330 buffer_put_int(&e->output, buffer_len(&msg));
331 buffer_append(&e->output, buffer_ptr(&msg),
332 buffer_len(&msg));
333 buffer_free(&msg);
334 xfree(data);
335 xfree(blob);
336 if (signature != NULL)
337 xfree(signature);
338 }
339
340 /* shared */
341 static void
342 process_remove_identity(SocketEntry *e, int version)
343 {
344 u_int blen, bits;
345 int success = 0;
346 Key *key = NULL;
347 u_char *blob;
348
349 switch (version) {
350 case 1:
351 key = key_new(KEY_RSA1);
352 bits = buffer_get_int(&e->request);
353 buffer_get_bignum(&e->request, key->rsa->e);
354 buffer_get_bignum(&e->request, key->rsa->n);
355
356 if (bits != key_size(key))
357 logit("Warning: identity keysize mismatch: actual %u, announced %u",
358 key_size(key), bits);
359 break;
360 case 2:
361 blob = buffer_get_string(&e->request, &blen);
362 key = key_from_blob(blob, blen);
363 xfree(blob);
364 break;
365 }
366 if (key != NULL) {
367 Identity *id = lookup_identity(key, version);
368 if (id != NULL) {
369 /*
370 * We have this key. Free the old key. Since we
371 * don\'t want to leave empty slots in the middle of
372 * the array, we actually free the key there and move
373 * all the entries between the empty slot and the end
374 * of the array.
375 */
376 Idtab *tab = idtab_lookup(version);
377 if (tab->nentries < 1)
378 fatal("process_remove_identity: "
379 "internal error: tab->nentries %d",
380 tab->nentries);
381 TAILQ_REMOVE(&tab->idlist, id, next);
382 free_identity(id);
383 tab->nentries--;
384 success = 1;
385 }
386 key_free(key);
387 }
388 buffer_put_int(&e->output, 1);
389 buffer_put_char(&e->output,
390 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
391 }
392
393 static void
394 process_remove_all_identities(SocketEntry *e, int version)
395 {
396 Idtab *tab = idtab_lookup(version);
397 Identity *id;
398
399 /* Loop over all identities and clear the keys. */
400 for (id = TAILQ_FIRST(&tab->idlist); id;
401 id = TAILQ_FIRST(&tab->idlist)) {
402 TAILQ_REMOVE(&tab->idlist, id, next);
403 free_identity(id);
404 }
405
406 /* Mark that there are no identities. */
407 tab->nentries = 0;
408
409 /* Send success. */
410 buffer_put_int(&e->output, 1);
411 buffer_put_char(&e->output, SSH_AGENT_SUCCESS);
412 }
413
414 static void
415 reaper(void)
416 {
417 u_int now = time(NULL);
418 Identity *id, *nxt;
419 int version;
420 Idtab *tab;
421
422 for (version = 1; version < 3; version++) {
423 tab = idtab_lookup(version);
424 for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
425 nxt = TAILQ_NEXT(id, next);
426 if (id->death != 0 && now >= id->death) {
427 TAILQ_REMOVE(&tab->idlist, id, next);
428 free_identity(id);
429 tab->nentries--;
430 }
431 }
432 }
433 }
434
435 static void
436 process_add_identity(SocketEntry *e, int version)
437 {
438 Idtab *tab = idtab_lookup(version);
439 int type, success = 0, death = 0, confirm = 0;
440 char *type_name, *comment;
441 Key *k = NULL;
442
443 switch (version) {
444 case 1:
445 k = key_new_private(KEY_RSA1);
446 (void) buffer_get_int(&e->request); /* ignored */
447 buffer_get_bignum(&e->request, k->rsa->n);
448 buffer_get_bignum(&e->request, k->rsa->e);
449 buffer_get_bignum(&e->request, k->rsa->d);
450 buffer_get_bignum(&e->request, k->rsa->iqmp);
451
452 /* SSH and SSL have p and q swapped */
453 buffer_get_bignum(&e->request, k->rsa->q); /* p */
454 buffer_get_bignum(&e->request, k->rsa->p); /* q */
455
456 /* Generate additional parameters */
457 rsa_generate_additional_parameters(k->rsa);
458 break;
459 case 2:
460 type_name = buffer_get_string(&e->request, NULL);
461 type = key_type_from_name(type_name);
462 xfree(type_name);
463 switch (type) {
464 case KEY_DSA:
465 k = key_new_private(type);
466 buffer_get_bignum2(&e->request, k->dsa->p);
467 buffer_get_bignum2(&e->request, k->dsa->q);
468 buffer_get_bignum2(&e->request, k->dsa->g);
469 buffer_get_bignum2(&e->request, k->dsa->pub_key);
470 buffer_get_bignum2(&e->request, k->dsa->priv_key);
471 break;
472 case KEY_RSA:
473 k = key_new_private(type);
474 buffer_get_bignum2(&e->request, k->rsa->n);
475 buffer_get_bignum2(&e->request, k->rsa->e);
476 buffer_get_bignum2(&e->request, k->rsa->d);
477 buffer_get_bignum2(&e->request, k->rsa->iqmp);
478 buffer_get_bignum2(&e->request, k->rsa->p);
479 buffer_get_bignum2(&e->request, k->rsa->q);
480
481 /* Generate additional parameters */
482 rsa_generate_additional_parameters(k->rsa);
483 break;
484 default:
485 buffer_clear(&e->request);
486 goto send;
487 }
488 break;
489 }
490 /* enable blinding */
491 switch (k->type) {
492 case KEY_RSA:
493 case KEY_RSA1:
494 if (RSA_blinding_on(k->rsa, NULL) != 1) {
495 error("process_add_identity: RSA_blinding_on failed");
496 key_free(k);
497 goto send;
498 }
499 break;
500 }
501 comment = buffer_get_string(&e->request, NULL);
502 if (k == NULL) {
503 xfree(comment);
504 goto send;
505 }
506 success = 1;
507 while (buffer_len(&e->request)) {
508 switch (buffer_get_char(&e->request)) {
509 case SSH_AGENT_CONSTRAIN_LIFETIME:
510 death = time(NULL) + buffer_get_int(&e->request);
511 break;
512 case SSH_AGENT_CONSTRAIN_CONFIRM:
513 confirm = 1;
514 break;
515 default:
516 break;
517 }
518 }
519 if (lifetime && !death)
520 death = time(NULL) + lifetime;
521 if (lookup_identity(k, version) == NULL) {
522 Identity *id = xmalloc(sizeof(Identity));
523 id->key = k;
524 id->comment = comment;
525 id->death = death;
526 id->confirm = confirm;
527 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
528 /* Increment the number of identities. */
529 tab->nentries++;
530 } else {
531 key_free(k);
532 xfree(comment);
533 }
534 send:
535 buffer_put_int(&e->output, 1);
536 buffer_put_char(&e->output,
537 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
538 }
539
540 /* XXX todo: encrypt sensitive data with passphrase */
541 static void
542 process_lock_agent(SocketEntry *e, int lock)
543 {
544 int success = 0;
545 char *passwd;
546
547 passwd = buffer_get_string(&e->request, NULL);
548 if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
549 locked = 0;
550 memset(lock_passwd, 0, strlen(lock_passwd));
551 xfree(lock_passwd);
552 lock_passwd = NULL;
553 success = 1;
554 } else if (!locked && lock) {
555 locked = 1;
556 lock_passwd = xstrdup(passwd);
557 success = 1;
558 }
559 memset(passwd, 0, strlen(passwd));
560 xfree(passwd);
561
562 buffer_put_int(&e->output, 1);
563 buffer_put_char(&e->output,
564 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
565 }
566
567 static void
568 no_identities(SocketEntry *e, u_int type)
569 {
570 Buffer msg;
571
572 buffer_init(&msg);
573 buffer_put_char(&msg,
574 (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
575 SSH_AGENT_RSA_IDENTITIES_ANSWER : SSH2_AGENT_IDENTITIES_ANSWER);
576 buffer_put_int(&msg, 0);
577 buffer_put_int(&e->output, buffer_len(&msg));
578 buffer_append(&e->output, buffer_ptr(&msg), buffer_len(&msg));
579 buffer_free(&msg);
580 }
581
582 #ifdef SMARTCARD
583 static void
584 process_add_smartcard_key (SocketEntry *e)
585 {
586 char *sc_reader_id = NULL, *pin;
587 int i, version, success = 0, death = 0, confirm = 0;
588 Key **keys, *k;
589 Identity *id;
590 Idtab *tab;
591
592 sc_reader_id = buffer_get_string(&e->request, NULL);
593 pin = buffer_get_string(&e->request, NULL);
594
595 while (buffer_len(&e->request)) {
596 switch (buffer_get_char(&e->request)) {
597 case SSH_AGENT_CONSTRAIN_LIFETIME:
598 death = time(NULL) + buffer_get_int(&e->request);
599 break;
600 case SSH_AGENT_CONSTRAIN_CONFIRM:
601 confirm = 1;
602 break;
603 default:
604 break;
605 }
606 }
607 if (lifetime && !death)
608 death = time(NULL) + lifetime;
609
610 keys = sc_get_keys(sc_reader_id, pin);
611 xfree(sc_reader_id);
612 xfree(pin);
613
614 if (keys == NULL || keys[0] == NULL) {
615 error("sc_get_keys failed");
616 goto send;
617 }
618 for (i = 0; keys[i] != NULL; i++) {
619 k = keys[i];
620 version = k->type == KEY_RSA1 ? 1 : 2;
621 tab = idtab_lookup(version);
622 if (lookup_identity(k, version) == NULL) {
623 id = xmalloc(sizeof(Identity));
624 id->key = k;
625 id->comment = sc_get_key_label(k);
626 id->death = death;
627 id->confirm = confirm;
628 TAILQ_INSERT_TAIL(&tab->idlist, id, next);
629 tab->nentries++;
630 success = 1;
631 } else {
632 key_free(k);
633 }
634 keys[i] = NULL;
635 }
636 xfree(keys);
637 send:
638 buffer_put_int(&e->output, 1);
639 buffer_put_char(&e->output,
640 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
641 }
642
643 static void
644 process_remove_smartcard_key(SocketEntry *e)
645 {
646 char *sc_reader_id = NULL, *pin;
647 int i, version, success = 0;
648 Key **keys, *k = NULL;
649 Identity *id;
650 Idtab *tab;
651
652 sc_reader_id = buffer_get_string(&e->request, NULL);
653 pin = buffer_get_string(&e->request, NULL);
654 keys = sc_get_keys(sc_reader_id, pin);
655 xfree(sc_reader_id);
656 xfree(pin);
657
658 if (keys == NULL || keys[0] == NULL) {
659 error("sc_get_keys failed");
660 goto send;
661 }
662 for (i = 0; keys[i] != NULL; i++) {
663 k = keys[i];
664 version = k->type == KEY_RSA1 ? 1 : 2;
665 if ((id = lookup_identity(k, version)) != NULL) {
666 tab = idtab_lookup(version);
667 TAILQ_REMOVE(&tab->idlist, id, next);
668 tab->nentries--;
669 free_identity(id);
670 success = 1;
671 }
672 key_free(k);
673 keys[i] = NULL;
674 }
675 xfree(keys);
676 send:
677 buffer_put_int(&e->output, 1);
678 buffer_put_char(&e->output,
679 success ? SSH_AGENT_SUCCESS : SSH_AGENT_FAILURE);
680 }
681 #endif /* SMARTCARD */
682
683 /* dispatch incoming messages */
684
685 static void
686 process_message(SocketEntry *e)
687 {
688 u_int msg_len, type;
689 u_char *cp;
690
691 /* kill dead keys */
692 reaper();
693
694 if (buffer_len(&e->input) < 5)
695 return; /* Incomplete message. */
696 cp = buffer_ptr(&e->input);
697 msg_len = GET_32BIT(cp);
698 if (msg_len > 256 * 1024) {
699 close_socket(e);
700 return;
701 }
702 if (buffer_len(&e->input) < msg_len + 4)
703 return;
704
705 /* move the current input to e->request */
706 buffer_consume(&e->input, 4);
707 buffer_clear(&e->request);
708 buffer_append(&e->request, buffer_ptr(&e->input), msg_len);
709 buffer_consume(&e->input, msg_len);
710 type = buffer_get_char(&e->request);
711
712 /* check wheter agent is locked */
713 if (locked && type != SSH_AGENTC_UNLOCK) {
714 buffer_clear(&e->request);
715 switch (type) {
716 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
717 case SSH2_AGENTC_REQUEST_IDENTITIES:
718 /* send empty lists */
719 no_identities(e, type);
720 break;
721 default:
722 /* send a fail message for all other request types */
723 buffer_put_int(&e->output, 1);
724 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
725 }
726 return;
727 }
728
729 debug("type %d", type);
730 switch (type) {
731 case SSH_AGENTC_LOCK:
732 case SSH_AGENTC_UNLOCK:
733 process_lock_agent(e, type == SSH_AGENTC_LOCK);
734 break;
735 /* ssh1 */
736 case SSH_AGENTC_RSA_CHALLENGE:
737 process_authentication_challenge1(e);
738 break;
739 case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
740 process_request_identities(e, 1);
741 break;
742 case SSH_AGENTC_ADD_RSA_IDENTITY:
743 case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
744 process_add_identity(e, 1);
745 break;
746 case SSH_AGENTC_REMOVE_RSA_IDENTITY:
747 process_remove_identity(e, 1);
748 break;
749 case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
750 process_remove_all_identities(e, 1);
751 break;
752 /* ssh2 */
753 case SSH2_AGENTC_SIGN_REQUEST:
754 process_sign_request2(e);
755 break;
756 case SSH2_AGENTC_REQUEST_IDENTITIES:
757 process_request_identities(e, 2);
758 break;
759 case SSH2_AGENTC_ADD_IDENTITY:
760 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
761 process_add_identity(e, 2);
762 break;
763 case SSH2_AGENTC_REMOVE_IDENTITY:
764 process_remove_identity(e, 2);
765 break;
766 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
767 process_remove_all_identities(e, 2);
768 break;
769 #ifdef SMARTCARD
770 case SSH_AGENTC_ADD_SMARTCARD_KEY:
771 case SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED:
772 process_add_smartcard_key(e);
773 break;
774 case SSH_AGENTC_REMOVE_SMARTCARD_KEY:
775 process_remove_smartcard_key(e);
776 break;
777 #endif /* SMARTCARD */
778 default:
779 /* Unknown message. Respond with failure. */
780 error("Unknown message %d", type);
781 buffer_clear(&e->request);
782 buffer_put_int(&e->output, 1);
783 buffer_put_char(&e->output, SSH_AGENT_FAILURE);
784 break;
785 }
786 }
787
788 static void
789 new_socket(sock_type type, int fd)
790 {
791 u_int i, old_alloc, new_alloc;
792
793 if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0)
794 error("fcntl O_NONBLOCK: %s", strerror(errno));
795
796 if (fd > max_fd)
797 max_fd = fd;
798
799 for (i = 0; i < sockets_alloc; i++)
800 if (sockets[i].type == AUTH_UNUSED) {
801 sockets[i].fd = fd;
802 buffer_init(&sockets[i].input);
803 buffer_init(&sockets[i].output);
804 buffer_init(&sockets[i].request);
805 sockets[i].type = type;
806 return;
807 }
808 old_alloc = sockets_alloc;
809 new_alloc = sockets_alloc + 10;
810 if (sockets)
811 sockets = xrealloc(sockets, new_alloc * sizeof(sockets[0]));
812 else
813 sockets = xmalloc(new_alloc * sizeof(sockets[0]));
814 for (i = old_alloc; i < new_alloc; i++)
815 sockets[i].type = AUTH_UNUSED;
816 sockets_alloc = new_alloc;
817 sockets[old_alloc].fd = fd;
818 buffer_init(&sockets[old_alloc].input);
819 buffer_init(&sockets[old_alloc].output);
820 buffer_init(&sockets[old_alloc].request);
821 sockets[old_alloc].type = type;
822 }
823
824 static int
825 prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, int *nallocp)
826 {
827 u_int i, sz;
828 int n = 0;
829
830 for (i = 0; i < sockets_alloc; i++) {
831 switch (sockets[i].type) {
832 case AUTH_SOCKET:
833 case AUTH_CONNECTION:
834 n = MAX(n, sockets[i].fd);
835 break;
836 case AUTH_UNUSED:
837 break;
838 default:
839 fatal("Unknown socket type %d", sockets[i].type);
840 break;
841 }
842 }
843
844 sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
845 if (*fdrp == NULL || sz > *nallocp) {
846 if (*fdrp)
847 xfree(*fdrp);
848 if (*fdwp)
849 xfree(*fdwp);
850 *fdrp = xmalloc(sz);
851 *fdwp = xmalloc(sz);
852 *nallocp = sz;
853 }
854 if (n < *fdl)
855 debug("XXX shrink: %d < %d", n, *fdl);
856 *fdl = n;
857 memset(*fdrp, 0, sz);
858 memset(*fdwp, 0, sz);
859
860 for (i = 0; i < sockets_alloc; i++) {
861 switch (sockets[i].type) {
862 case AUTH_SOCKET:
863 case AUTH_CONNECTION:
864 FD_SET(sockets[i].fd, *fdrp);
865 if (buffer_len(&sockets[i].output) > 0)
866 FD_SET(sockets[i].fd, *fdwp);
867 break;
868 default:
869 break;
870 }
871 }
872 return (1);
873 }
874
875 static void
876 after_select(fd_set *readset, fd_set *writeset)
877 {
878 struct sockaddr_un sunaddr;
879 socklen_t slen;
880 char buf[1024];
881 int len, sock;
882 u_int i;
883 uid_t euid;
884 gid_t egid;
885
886 for (i = 0; i < sockets_alloc; i++)
887 switch (sockets[i].type) {
888 case AUTH_UNUSED:
889 break;
890 case AUTH_SOCKET:
891 if (FD_ISSET(sockets[i].fd, readset)) {
892 slen = sizeof(sunaddr);
893 sock = accept(sockets[i].fd,
894 (struct sockaddr *) &sunaddr, &slen);
895 if (sock < 0) {
896 error("accept from AUTH_SOCKET: %s",
897 strerror(errno));
898 break;
899 }
900 if (getpeereid(sock, &euid, &egid) < 0) {
901 error("getpeereid %d failed: %s",
902 sock, strerror(errno));
903 close(sock);
904 break;
905 }
906 if ((euid != 0) && (getuid() != euid)) {
907 error("uid mismatch: "
908 "peer euid %u != uid %u",
909 (u_int) euid, (u_int) getuid());
910 close(sock);
911 break;
912 }
913 new_socket(AUTH_CONNECTION, sock);
914 }
915 break;
916 case AUTH_CONNECTION:
917 if (buffer_len(&sockets[i].output) > 0 &&
918 FD_ISSET(sockets[i].fd, writeset)) {
919 do {
920 len = write(sockets[i].fd,
921 buffer_ptr(&sockets[i].output),
922 buffer_len(&sockets[i].output));
923 if (len == -1 && (errno == EAGAIN ||
924 errno == EINTR))
925 continue;
926 break;
927 } while (1);
928 if (len <= 0) {
929 close_socket(&sockets[i]);
930 break;
931 }
932 buffer_consume(&sockets[i].output, len);
933 }
934 if (FD_ISSET(sockets[i].fd, readset)) {
935 do {
936 len = read(sockets[i].fd, buf, sizeof(buf));
937 if (len == -1 && (errno == EAGAIN ||
938 errno == EINTR))
939 continue;
940 break;
941 } while (1);
942 if (len <= 0) {
943 close_socket(&sockets[i]);
944 break;
945 }
946 buffer_append(&sockets[i].input, buf, len);
947 process_message(&sockets[i]);
948 }
949 break;
950 default:
951 fatal("Unknown type %d", sockets[i].type);
952 }
953 }
954
955 static void
956 cleanup_socket(void)
957 {
958 if (socket_name[0])
959 unlink(socket_name);
960 if (socket_dir[0])
961 rmdir(socket_dir);
962 }
963
964 void
965 cleanup_exit(int i)
966 {
967 cleanup_socket();
968 _exit(i);
969 }
970
971 static void
972 cleanup_handler(int sig)
973 {
974 cleanup_socket();
975 _exit(2);
976 }
977
978 static void
979 check_parent_exists(int sig)
980 {
981 int save_errno = errno;
982
983 if (parent_pid != -1 && kill(parent_pid, 0) < 0) {
984 /* printf("Parent has died - Authentication agent exiting.\n"); */
985 cleanup_handler(sig); /* safe */
986 }
987 mysignal(SIGALRM, check_parent_exists);
988 alarm(10);
989 errno = save_errno;
990 }
991
992 static void
993 usage(void)
994 {
995 fprintf(stderr, "Usage: %s [options] [command [args ...]]\n",
996 __progname);
997 fprintf(stderr, "Options:\n");
998 fprintf(stderr, " -c Generate C-shell commands on stdout.\n");
999 fprintf(stderr, " -s Generate Bourne shell commands on stdout.\n");
1000 fprintf(stderr, " -k Kill the current agent.\n");
1001 fprintf(stderr, " -d Debug mode.\n");
1002 fprintf(stderr, " -a socket Bind agent socket to given name.\n");
1003 fprintf(stderr, " -t life Default identity lifetime (seconds).\n");
1004 exit(1);
1005 }
1006
1007 int
1008 main(int ac, char **av)
1009 {
1010 int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
1011 int sock, fd, ch, nalloc;
1012 char *shell, *format, *pidstr, *agentsocket = NULL;
1013 fd_set *readsetp = NULL, *writesetp = NULL;
1014 struct sockaddr_un sunaddr;
1015 #ifdef HAVE_SETRLIMIT
1016 struct rlimit rlim;
1017 #endif
1018 #ifdef HAVE_CYGWIN
1019 int prev_mask;
1020 #endif
1021 extern int optind;
1022 extern char *optarg;
1023 pid_t pid;
1024 char pidstrbuf[1 + 3 * sizeof pid];
1025
1026 /* drop */
1027 setegid(getgid());
1028 setgid(getgid());
1029
1030 #if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
1031 /* Disable ptrace on Linux without sgid bit */
1032 prctl(PR_SET_DUMPABLE, 0);
1033 #endif
1034
1035 SSLeay_add_all_algorithms();
1036
1037 __progname = ssh_get_progname(av[0]);
1038 init_rng();
1039 seed_rng();
1040
1041 while ((ch = getopt(ac, av, "cdksa:t:")) != -1) {
1042 switch (ch) {
1043 case 'c':
1044 if (s_flag)
1045 usage();
1046 c_flag++;
1047 break;
1048 case 'k':
1049 k_flag++;
1050 break;
1051 case 's':
1052 if (c_flag)
1053 usage();
1054 s_flag++;
1055 break;
1056 case 'd':
1057 if (d_flag)
1058 usage();
1059 d_flag++;
1060 break;
1061 case 'a':
1062 agentsocket = optarg;
1063 break;
1064 case 't':
1065 if ((lifetime = convtime(optarg)) == -1) {
1066 fprintf(stderr, "Invalid lifetime\n");
1067 usage();
1068 }
1069 break;
1070 default:
1071 usage();
1072 }
1073 }
1074 ac -= optind;
1075 av += optind;
1076
1077 if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
1078 usage();
1079
1080 if (ac == 0 && !c_flag && !s_flag) {
1081 shell = getenv("SHELL");
1082 if (shell != NULL && strncmp(shell + strlen(shell) - 3, "csh", 3) == 0)
1083 c_flag = 1;
1084 }
1085 if (k_flag) {
1086 pidstr = getenv(SSH_AGENTPID_ENV_NAME);
1087 if (pidstr == NULL) {
1088 fprintf(stderr, "%s not set, cannot kill agent\n",
1089 SSH_AGENTPID_ENV_NAME);
1090 exit(1);
1091 }
1092 pid = atoi(pidstr);
1093 if (pid < 1) {
1094 fprintf(stderr, "%s=\"%s\", which is not a good PID\n",
1095 SSH_AGENTPID_ENV_NAME, pidstr);
1096 exit(1);
1097 }
1098 if (kill(pid, SIGTERM) == -1) {
1099 perror("kill");
1100 exit(1);
1101 }
1102 format = c_flag ? "unsetenv %s;\n" : "unset %s;\n";
1103 printf(format, SSH_AUTHSOCKET_ENV_NAME);
1104 printf(format, SSH_AGENTPID_ENV_NAME);
1105 printf("echo Agent pid %ld killed;\n", (long)pid);
1106 exit(0);
1107 }
1108 parent_pid = getpid();
1109
1110 if (agentsocket == NULL) {
1111 /* Create private directory for agent socket */
1112 strlcpy(socket_dir, "/tmp/ssh-XXXXXXXXXX", sizeof socket_dir);
1113 if (mkdtemp(socket_dir) == NULL) {
1114 perror("mkdtemp: private socket dir");
1115 exit(1);
1116 }
1117 snprintf(socket_name, sizeof socket_name, "%s/agent.%ld", socket_dir,
1118 (long)parent_pid);
1119 } else {
1120 /* Try to use specified agent socket */
1121 socket_dir[0] = '\0';
1122 strlcpy(socket_name, agentsocket, sizeof socket_name);
1123 }
1124
1125 /*
1126 * Create socket early so it will exist before command gets run from
1127 * the parent.
1128 */
1129 sock = socket(AF_UNIX, SOCK_STREAM, 0);
1130 if (sock < 0) {
1131 perror("socket");
1132 cleanup_exit(1);
1133 }
1134 memset(&sunaddr, 0, sizeof(sunaddr));
1135 sunaddr.sun_family = AF_UNIX;
1136 strlcpy(sunaddr.sun_path, socket_name, sizeof(sunaddr.sun_path));
1137 #ifdef HAVE_CYGWIN
1138 prev_mask = umask(0177);
1139 #endif
1140 if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) {
1141 perror("bind");
1142 #ifdef HAVE_CYGWIN
1143 umask(prev_mask);
1144 #endif
1145 cleanup_exit(1);
1146 }
1147 #ifdef HAVE_CYGWIN
1148 umask(prev_mask);
1149 #endif
1150 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1151 perror("listen");
1152 cleanup_exit(1);
1153 }
1154
1155 /*
1156 * Fork, and have the parent execute the command, if any, or present
1157 * the socket data. The child continues as the authentication agent.
1158 */
1159 if (d_flag) {
1160 log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
1161 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1162 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1163 SSH_AUTHSOCKET_ENV_NAME);
1164 printf("echo Agent pid %ld;\n", (long)parent_pid);
1165 goto skip;
1166 }
1167 pid = fork();
1168 if (pid == -1) {
1169 perror("fork");
1170 cleanup_exit(1);
1171 }
1172 if (pid != 0) { /* Parent - execute the given command. */
1173 close(sock);
1174 snprintf(pidstrbuf, sizeof pidstrbuf, "%ld", (long)pid);
1175 if (ac == 0) {
1176 format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
1177 printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
1178 SSH_AUTHSOCKET_ENV_NAME);
1179 printf(format, SSH_AGENTPID_ENV_NAME, pidstrbuf,
1180 SSH_AGENTPID_ENV_NAME);
1181 printf("echo Agent pid %ld;\n", (long)pid);
1182 exit(0);
1183 }
1184 if (setenv(SSH_AUTHSOCKET_ENV_NAME, socket_name, 1) == -1 ||
1185 setenv(SSH_AGENTPID_ENV_NAME, pidstrbuf, 1) == -1) {
1186 perror("setenv");
1187 exit(1);
1188 }
1189 execvp(av[0], av);
1190 perror(av[0]);
1191 exit(1);
1192 }
1193 /* child */
1194 log_init(__progname, SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_AUTH, 0);
1195
1196 if (setsid() == -1) {
1197 error("setsid: %s", strerror(errno));
1198 cleanup_exit(1);
1199 }
1200
1201 (void)chdir("/");
1202 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1203 /* XXX might close listen socket */
1204 (void)dup2(fd, STDIN_FILENO);
1205 (void)dup2(fd, STDOUT_FILENO);
1206 (void)dup2(fd, STDERR_FILENO);
1207 if (fd > 2)
1208 close(fd);
1209 }
1210
1211 #ifdef HAVE_SETRLIMIT
1212 /* deny core dumps, since memory contains unencrypted private keys */
1213 rlim.rlim_cur = rlim.rlim_max = 0;
1214 if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
1215 error("setrlimit RLIMIT_CORE: %s", strerror(errno));
1216 cleanup_exit(1);
1217 }
1218 #endif
1219
1220 skip:
1221 new_socket(AUTH_SOCKET, sock);
1222 if (ac > 0) {
1223 mysignal(SIGALRM, check_parent_exists);
1224 alarm(10);
1225 }
1226 idtab_init();
1227 if (!d_flag)
1228 signal(SIGINT, SIG_IGN);
1229 signal(SIGPIPE, SIG_IGN);
1230 signal(SIGHUP, cleanup_handler);
1231 signal(SIGTERM, cleanup_handler);
1232 nalloc = 0;
1233
1234 while (1) {
1235 prepare_select(&readsetp, &writesetp, &max_fd, &nalloc);
1236 if (select(max_fd + 1, readsetp, writesetp, NULL, NULL) < 0) {
1237 if (errno == EINTR)
1238 continue;
1239 fatal("select: %s", strerror(errno));
1240 }
1241 after_select(readsetp, writesetp);
1242 }
1243 /* NOTREACHED */
1244 }
DragonFly BSD